Global warming, the phenomenon of increasing averageairtemperaturesnear the surface ofEarthover the past one to two centuries. Climate scientists have since the mid-20th century gathered detailed observations of variousweatherphenomena (such as temperatures,precipitation, and storms) and of related influences onclimate(such asocean currentsand the atmosphere’s chemical composition). These data indicate that Earth’sclimatehas changed over almost every conceivable timescale since the beginning of geologic time and that the influence ofhumanactivities since at least the beginning of theIndustrial Revolutionhas been deeply woven into the very fabric ofclimate change.

increase in certain gases which heat the earth surface and cause harmful effects on earth is global warming

a gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, CFCs, and other pollutants.

Global warmingis a long-term rise in the average temperature of theEarth'sclimate system, an aspect ofclimate changeshown bytemperature measurementsand by multiple effects of the warming.